1. Field of the Invention
The invention is related to the field of wireless communications, and in particular, to methods for using an echo plug that plugs into the hands-free jack of a wireless telephone to test wireless telephones and communication systems.
2. Background of the Invention
The demand for wireless communication services is growing dramatically, and there is corresponding growth in the need to test wireless telephones and communication systems. A common testing technique uses a test system that is equipped with a transmit telephone circuit and a receive telephone circuit. The transmit telephone circuit places a test call to the receive telephone circuit over a wireless telephone. The transmit telephone circuit then transmits test signals over the call connection to the receive telephone circuitry. The test system compares the received test signals to the transmitted test signals to generate statistics regarding voice quality and round-trip delay. One example of a test system is the Voice Quality Tester supplied by Agilent Technologies. Two common voice quality measurements are Perceptual Speech Quality Measure (PSQM) and Perceptual Analysis Measurement System (PAMS).
The above-described test call is placed as follows. The transmit telephone circuit is connected to a wireless telephone using a special connector that is customized for the wireless telephone. The receive telephone circuit is connected to a telephone jack that is coupled to the communication network. The wireless telephone places a test call using a test telephone number. A wireless transceiver in the communication system handles the test call from the wireless telephone, and the communication system routes the call to the telephone jack. The receive telephone circuit that is connected to the telephone jack answers the call. The test system is now connected to a communications loop through the communication network and is ready to conduct voice quality and delay tests.
Wireless telephone suppliers and service providers need to test their equipment under various conditions to ensure quality. Unfortunately, the above-described testing technique inhibits robust testing under dynamic test conditions. For example, the test system is coupled to the wireless telephone with a special connector that is not compatible with other types of wireless telephones. Many wireless telephones do not have their own special connectors, and even if they did, the use of many different special connectors is cumbersome. As a result, the test system cannot effectively test many different types of wireless telephones. In addition to this restriction, mobility testing is cumbersome because the test system must be moved along with the wireless telephone.
The public telephone network internally performs similar tests. On a percentage of calls, the originating telephone switch requests a continuity test in the call set-up signaling message. In response to the request, the terminating telephone switch cross-connects the connections for the call. The originating telephone switch then transmits a tone to the terminating telephone switch where the tone is looped back to the originating telephone switch. The continuity test is successful if the originating telephone switch receives the tone. Continuity testing is inadequate to test wireless telephones and communication systems.
The invention solves the above problem with methods for testing wireless telephones and communication systems under dynamic test conditions. An echo plug is used to loop test signals through a wireless telephone and back to a test system. The echo plug fits into the hands-free jack of a wireless telephone and is easily moved from one wireless telephone to another. The wireless telephones retain their mobility with the echo plug attached. The echo plug facilitates the testing of different wireless telephones at various locations over different communication systems.
In one method, an echo plug is plugged into a hands-free jack of a wireless telephone. A test call is generated between the test system and the wireless telephone. The test system transmits a test signal to the wireless telephone over the test call. The echo plug loops the test signal from a speaker connection of the hands-free jack to a microphone connection of the hands-free jack. The wireless telephone transmits the test signal to the test system over the test call. The test system generates test results in response to the test signal.
In another method, the echo plug is plugged into hands-free jacks of two wireless telephones. Two test calls are generated between the test system and the two wireless telephones. The test system transmits a test signal to the first wireless telephone over the first test call. The echo plug loops the test signal from a speaker connection of the hands-free jack in the first wireless telephone to a microphone connection of the hands-free jack in the second wireless telephone. The second wireless telephone transmits the test signal to the test system over the second test call. The test system generates test results in response to the test signal.